Hi all,
I'm working on a project and I want to build the circuit in the image. I wanted to know if I can replace the ceramic capacitors that are shown in the diagram for electrolytic capacitors. If so, how should I connect them? I mean, how should I manage the electrolytic's polarity?
Thanks in advance!
I'd think the AC source indicated would be a problem for an electrolytic cap.
oh... ok.. thanks!
Another question...I've been checking the diagram more deeply but I'm not sure what everything means.. I'm supposed to connect a piezoelectric in this circuit but I'm not really sure where should I put it :~. Also, I don't understand what Vbias means...
Thanks again! =)
If the signal source is a piezo element then its already a capacitor (piezo element is basically a ceramic capacitor that flexes!)
and you can lose the first capacitor. The second capacitor has AC across it so you can only use an electrolytic if the amplitude
is small (significant reverse voltage on an electrolytic will degrade it). There are specialized non-polarized electrolytics available,
or you can use two electrolytics back-to-back (each twice the capacitance) to handle larger AC voltages.
The bias voltage keeps the voltages in the range of operation of the opamp - the output signal will vary about this level, usually
one would use half the supply voltage.
Thank you very much!
What type of op amp is it? If it has low enough input bas current, you can scale the resistor values up by some factor and scale the capacitor values down by the same factor. That will make it easier to get ceramic or other non-polarised capacitors because the values will be lower. The input resistance will go up as well, but that either won't matter or will be a good thing, depending on what is driving it.
The bias voltage keeps the voltages in the range of operation of the opamp
- the output signal will vary about this level, usually
one would use half the supply voltage.
To add 1 more bit of info, this is what you do if the opAmp is using +5V and gnd to
power, rather than +/-5V. If you have the latter, then Vbias can be 0V.